Engine driving mechanism for magnetos



` April 22 1941 J. F. MARTIN ET AL 2,239,650

ENGINE DRIVING MECHANSM FOR MAGNETOS Filed March 19, 1940 3 Sl'leets-Sheel,v 1

ATTORNEY.

April 22, 1941. J. F. MARTIN ETAL 2,239,650

ENGINE DRIVING MECHANISM FOR MAGNETOS Filed March 19 1940 V 5 SheetSSheet 2 April 22, 1941# J. F. MARTIN ETA. 2,239,650

ENGINE DRIVING MECHANIASM FOR MAGNETOS Filed March 19, 1940 3 Sheets-Sheet 3 Z i JJZ 7 Q l I 'I i7 o 'wl/A INVENTORS Patented Apr. 22, 1941 ENGINE DRIVING LIECHANISM FOR MAGNETOS John F. Martin and William D. Crocker, Springfield, Mass., assignors to American Bosch Corporation, Sprngeld, Mass., a. corporation of New York Application March 19, 1940, Serial No. 324,778

Claims.

The present invention relates to engine driving mechanisms with and without couplings, whether impulse couplings or drive couplings or both, for operating magnetos for electrical ignition of associated internal combusion engines.

The primary object of the invention is to provide compact and inexpensive driving mechanisms which, by reason of their few and simple parts, result in rugged and durable constructions producing effective ignition for reliable operation of engines over long periods of service under severe field conditions. These results are attained principally by constructions in which the magneto bearing or the magneto operating shaft provides the sole support, whether directly or indirectly, for one end of the engine driving mechanism, whereby the necessity for a separate bearing and oil seal for that end of said mechnism if obviated.

Another object is to provide a housing for the parts which preferably not only supports the magneto in adjustable position but also supports the outer end of the drive shaft of the engine driving mechanism, so that the magneto and drive shafts may be assembled and maintained in proper alinement.

Still another object is to provide such arrangements that, if desired, a governor can be advantageously associated with the driving mechanisms for controlling the engine.

Other objects Will appear from the following description of several illustrative embodiments of the invention taken in connection with the accompanying drawings, of which Fig. 1 shows an arrangement, mostly in sectional elevation, in which the projecting end of the operating shaft of a rotary magneto is journaled in the driving member of an impulse coupling for the magneto to support the inner end of the engine driving mechanism incorporating a governor also, the magneto being flange-mounted on the engine casing; Fig. 2 is a fragmentary view in section of a similar arrangement except that a drive coupling in addition to the impulse coupling is incorporated in the engine driving mechanism; Fig. 3 is a fragmentary View in section on reduced scale of an arrangement similar to Fig. 2 except that the magneto operating shaft supports one end of the engine driving mechanism by means of a nut journaled in the shaft of said mechanism and fastened onA the magneto shaft in position to hold the members of the impulse coupling in position thereon; Fig. 4 is a fragmentary View in lsection on reduced scale of an arrangement similar to Fig. 2 except that no impulsespective governor Weights 26.

coupling is used but the drive coupling alone; and Fig. 5 is a fragmentary View in section of an arrangement in which neither an impulse coupling nor a drive coupling is used, the magneto operating shaft being extended to form also the shaft of the engine driving mechanism.

Referring to Fig. 1, the magneto I of any suitable type has an integral mounting flange 2 of well known kind fastened in angularly adjusted position tothe engine casing members 3 and 4 by bolts 5 passing through the circular slots 6 of the ange. This mounting provides a pocket at 'I for the exteriorly projecting end of the magneto operating shaft 8, which is supported by the ball bearing 9 in the mageto and extends through the oil seal I0. On shaft 8 is rigidly fastened the driven member II of an impulse coupling of any suitable type, which member is preferably keyed and held longitudinally thereon by nut I2 and lock vWasher I3. The cooperating driving member of the impulse coupling has a cup-shaped housing I4 integral with the engine drive shaft I5 and a bearing I6 in which the end of shaft 8 is journaled. The engine driving mechanism, incorporating the impulse coupling and the engine drive shaft, as well as the gear and governor hereinafter referred to, is thus supported at its inner end by the magneto operating shaft 8 or primarily by the magneto bearing 9, and is supported at its outer end in the bearing II of the end cover I8. Intermediate the ends of shaft I5 is mounted a governor I9, and near the impulse coupling member I4, between it and the governor, is mounted a gear 29 which is meshed or otherwise driven by the engine gear 2l in proper lratio and timing. The gear 20 is fixed rotatively on shaft I5 by a key 22 and is held longitudinally thereon by a hub 23 pinned at 24 to the shaft. The hub carries oppositely disposed bracket arms 25 to which are pivoted re- E'ach weight has a camming projection 21 adapted to push against the collar 28 which has a ball thrust bearing against disc 29 loose on the shaft. Surrounding the engine driving mechanism is a housing including the members 3 and 4 and the end cover I8 fastened thereto by bolts 39. This cover also carries bearings (not shown) for the cross shaft 3l on which is fixedly mounted the cam 32 abutting the disc 29 inside the housing and the arm 33 outside the housing. A tension spring 34 is outward position of its throw to limit through link 31 the maximum open position of throttle lever 38 of the engine.

Referring now to the embodiment of Fig. 2, it will be observed that shaft 39 of the engine driving mechanism is not integral with the driving member 49 of the impulse coupling, as in Fig. l, but is mechanically connected thereto by a coupling member 4l of the Oldham type of drive coupling so that the impulse coupling with its fastening nut 42 and tongue 43 may be standard. Furthermore, the exteriorly projecting end of the magneto shaft 44 extends into bearing 45 in shaft 39 on which member 4I of .the coupling is brazed against a shoulder vat theend of the shaft 39. In this embodiment also, the engine driving mechanism, including in this case a drive coupling as well as an impulse coupling, is directly supported at one end by the magneto operating shaft and indirectly by the magneto bearing 9.

The embodiment of Fig. 3 is like thatof Fig. 2, except that the lock nut 46 not only holds the impulse coupling members in place longitudinally but its extended end portion 41 is journaled in an interior bearing of shaft 39. The lock screw 48 holds nut 46 securely in place. In Fig. 4 there is no impulse coupling for the magneto as in the previous embodiments, but a drive coupling only, the end of the operating shaft 50 being j ournaled in an interior bearing of shaft 39. noted before, in these embodiments it is the magneto operating shaft directly and the magneto bearing indirectly that support one end of the engine driving mechanism.

In the embodiment of Fig. 5 there is no coupling, impulse or drive coupling, but the shaft 5l is both the operating shaft of the magneto and the drive shaft of the engine driving mechanism. In thi-s case, the magneto bearing 9 supports that shaft directly.

During the starting period of the engine with any of the driving mechanisms 0f Figs. 1 to 3, the magneto is impulsed by the impulse coupling in the well known way, the magneto and engine shafts appropriately turning with respect to one another, but above a` predetermined speed the drive of the magneto is direct through the spring 52 of the impulse coupling. In the other embodiments, the magneto is driven directly during the starting period also, through the drive coupling in Fig. 4 and by an integral shaft in Fig. 5. As the engine speed increases further in any of the embodiments incorporating a governor, the weights 26 fly out, moving the disc 29 to the right in Fig, 1 and through the cam 32 swinging the arm 33 toward the broken line position against the tension of spring 34. At a predetermined hign speed of the engine the arm begins to compress the bumper spring 36 until the solid position thereof prevents further movement of the engine throttle beyond this fully open position. As the engine throttle is moved toward its closed position at any time, the spring 34 keeps the cam 32 against the disc 29. The shape of the face of the cam 32 xes the relation between the longitudinal movement of the disc 29 and the swinging movement of the arm 33, and therefore predetermines the control of the gas supply in accordance with the speed of the engine.

From the foregoing it will be observed that `by mounting the gear 26 between the magneto I and the governor I9 when a governor is incorporated in the engine driving mechanism, and near the coupling when such is provided, the engine drive shaft is subjected to .the minimum However, as ,l

torsional effects. Also by this construction, the magneto bearing 9 directly or indirectly, and in some cases the overhanging end of the magneto operating shaft directly, forms the sole support for one end of the engine driving mechanism, whether an impulse coupling and a drive coupling are used or either or neither of them is used. Thereby the necessity for an additional bearing and engine oil seal at that end of the `drive shaft is eliminated. This results in a reduction in wear, vibration and noise and an increase in efficiency, dependability and life of the engine driving mechanism, including the governor when used. Furthermore, the engine driving mechanism is more compact and less eX- pensive.

It is obvious that in any of the illustrated embodiments, the magneto may be base-mounted or otherwise supported to be driven by the engine driving mechanism, for rotary, oscillatory or other kind of operation; also the impulse coupling of the embodiment of Fig. 1, 2 or 3 may be dispensed with, as in Fig. 4 or 5, or the drive coupling of Fig. 2, 3 or 4 may be dispensed with as in Fig. 1 or 2. Furthermore, the nut construction of Fig. 3 may be adapted to the embodiments of Figs. 1, 2 and 4. The engine governor may or may not be incorporated in any of the embodiments. It will be understood that these and other modifications are intended to be covered by the appended claims within the broad terms thereof in which the term coupling is intended to cover an impulse coupling or a drive coupling, each of any suitable type, and in which engine driving mechanism supported by the magneto bearing is intended to cover such mechanism supported thereby either directly or indirectly, as aforesaid.

Having thus described our invention, what we claim is:

l. In combination; a magneto having an operating shaft for operation by an engine and also having a bearing for said shaft arranged within the magneto; and engine driving mechanism connected to the magneto shaft; the engine driving mechanism being supported at the magneto end by the magneto bearing solely.

2. In combination; a magneto having an operating shaft projecting exteriorly thereof for operation by an engine; and engine driving mechanism connected to the projecting part of the magneto shaft; the engine driving mechan'ism being supported at that end by the magneto shaft solely.

3. In combination; a magneto having an operating shaft projecting exteriorly thereof for operation by an engine; and an engine drive shaft having an exterior bearing in which the projecting end of the magneto shaft is journaled to form the sole support of the engine shaft at that end.

4. In combination; a magneto having an operating shaft projecting exteriorly thereof for operation by an engine; an engine drive shaft; and a coupling having its driving member rigidly connected to the engine shaft and its driven member rigidly connected to the projecting part of the magneto shaft; the projecting end of the magneto shaft being journaled in the engine shaft to form the sole support of the engine shaft at that end.

5. In combination; a magneto having an operating shaft projecting eXterio-rly thereof for operation by an engine; an engine drive shaft;

anda coupling having its driving member rigidly connected to the engine shaft and its driven member rigidly connected to the projecting part of the magneto shaft; the projecting end of the magneto shaft being journaled in the driving member of the coupling to form the sole support of the engine shaft at that end.

6. In combination; a magneto having an operating shaft projecting exteriorly thereof for operation by an engine; an engine drive shaft; an impulse coupling having its driven member rigidly fastened on the magneto shaft; and a drive coupling having its driving member rigidly fastened on the engine shaft and its driven member connected to the driving member of the impulse coupling; the magneto shaft being journaled in the engine shaft to form the sole support of the engine shaft at that end.

7. In combination; a magneto having an operating shaft projecting exteriorly thereof for operation by an engine; an engine drive shaft; and a coupling having its driving member rigidly fastened on the engine shaft and also having a lock nut on the magneto shaft rigidly fastening the driven member of the coupling thereon; the lock nut being journaled in the engine shaft to form the sole support of the engine shaft at that end.

8. In combination; an engine casing; a magneto supported by the casing and having an operating shaft and a bearing for said shaft arranged within the magneto; and engine driving mechanism connected to the magneto shaft; the engine driving mechanism being supported at the magneto end by the magneto bearingsolely and at the other end by the casing.

9. In combination; an engine casing; a magneto supported by the casing with its operating shaft projecting exteriorly of the magneto into the casing for operation by the engine; and engine driving mechanism connected to a projecting part of the magneto shaft; the engine driving mechanism being suppo-rted at the magneto end by the magneto shaft solely and at the other end by the casing.

10. In combination; an engine casing; a magneto adjustably supported by the casing With its operating shaft projecting exteriorly of the magneto into the casing for operation by the engine; an engine drive shaft connected to the l 

